Hey Prathmesh,

There are four laws of thermodynamics: Zeroth law, First Law, Second Law, Third Law.

The Second Law of Thermodynamics states that the state of entropy of the entire universe, as an isolated system will always increase over time. The second law also states that the changes in the entropy in the universe can never be negative.

To brief this law, we can say that the entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium.

Hope this helps!

Hi Prathmesh,

The second law of thermodynamics states that the total entropy of an isolated system can never decrease over time, and is constant if and only if all processes are reversible. Isolated systems spontaneously evolve towards thermodynamic equilibrium  the state with maximum entropy.

OR

1-Entropy of universe increases.( the changes in the entropy in the universe can never be negative).

2-All natural process are reversible.

3-It is not possible to construct machine which is 100 percent efficient.(i.e to convert all heat into work without passing into surrounding)

Hope this helps,please feel free to ask if you have any further queries.

Thank You.